Herbicidal oils



Patented-June e, 1939 UNITED ST T S PATENT oF-ncs Hann re ions James Prince Warner and Alexis Voorhies, In,

aware La'., assignors to Standard Oil Development Company, a

corporation of Del- No Drawing. Application October 3, 1035, Serial No. 43,384

dclaims.

This invention relates to herbicidal oils and relates particularly to herbicidal oils that are of special value in the control of perennial weeds such as hurdocks, dandelions, Bermuda grassw, and other growths having a deep underground root system. These herbicidal oils are also especially useful, besides killing the perennial weeds, in preventing the growth of these perennial weeds, and other undesirable growths, According to this invention highly toxic herbicidal oils are prepared from mineral oils. These herbicidal oils are preferably produced by the destructive hydrogenation of mineral oils, the min eral oil being either .a straight run or cracked oil or an oil made by selective extraction of a straight run or cracked oil- The oils from which these herbicidal oils are derived may he of a boiling range including that of gasoline and extending up to 700 F. or somewhat higher. In addition-to destructive hydrogenation, other methods of producing these herbicidal oils are high'temperature cracking ofv liquid or gaseous hydrocarbons or.

mixtures thereof, or selective extractions of suitable base stocks, Herbicidal oils so produced are found to contain a substantial amount of 8.1191- matic hydrocarbons together with naphthenic:

and unsaturated hydrocarbons; g

In the preferred destructive hydrogenation process, these distillate oils as such or fractions by the use of selective solvents, are vaporphase with hydrogen over suit-' separatedv passed in able catalysts at a pressurein excess of 20 atmospheres and preferably at a pressure of- 100 to 200 atmospheres or higher, and at atemperature above about 900 F. and preferably within the range of about 930f-1050 F. with asuitablepartial pressure of hydrogenand time of. co'ntact to secure destructive hydrogenation without the formation of appreciable amounts of polymerized .orj' coky material.

. The hydrogen recycled with the oills'pr'eferably within the range of LOW-10,000 cubic feet per barrel of feed oil and the 'is preferably feet per barrel of depending upon the =the.charging stock. y A greater proportion of hydrogen may be used with suitable variation in feed rate, temperature feed oil, the amount generally gravity and boiling range of so 'andpressure as is known in the art. The feed rate dependsupon the reaction temperature and other operating conditions, sure of hydrogen, and may be suitably about 0.75 to 4 volumesof oil per volume of catalyst filled reaction space per hour. The

hydrogen consumed. within the range of 500-2500 cubic such as the partial pres-' the purposeof this invention and the claims.

- oil of known and relatively high found to preferably comprise the oxides or sulfides of the metals of the VI group of elementswith suitable promoters of the alkaline earth and earth oxides. Such catalysts are insensitive to sulfur poisoning and are suitably classified as sulf-active. 5 The product of such vapor phase destructive hydrogenation of petroleum distillates or hydroforming process is called a hydroformedoil for This hydroformed oil isfractionated and the fraction having a low aniline pointsuch as 20 F. to '-80? F. andagravity of about 8 to 20 A. P. I. has been found most suitable as a herbicidal oil. Extractives obtained by extracting suitable base stocks with selective solvents and having 15 similar aniline points are also suitable for use as herbicidal oils. Highly cracked oilsj-fromsuitable base stocks having similar aniline points are also suitable for use as herbicidal oils. The oils that contain substantial amounts of aromatic hydrog0 carbons were-found to be more effective than oils that are olefinic. Aniline points lower than the freezing point of'aniline are determined by mix ing the low aniline point 011 under test with an aniline point and g5 terminlng by graphical extracalculating or own/low aniline point from that polation the of the mixture.

These herbicidal oils were found to have toxicitiesbetween 0.01 and 0.02% when compared so with the toxicity of coal tar creosote tested by the samemethod and whose toxicity is usually about 0.05%. These herbicidal oils were therefore be. more toxic than coal tar creosote by this method of test. The toxicity tests on -the wood preservatives were made in nutrient agar medium with the standard fungus fomes annosus. Of the herbicidal oil used in the above case, nearly 90% distills between 392 and 518 F. When all the oil is distilled up to 639 F. there 40 is still a small residue but there is no strong indication of decomposition. The oil is completely sulfcnated by sulfuric acid of the strength 'usually recommended for this test on creosote, that is, it showsj no evidence of containing any large amounts ofparailin hydrocarbons.

These herbicidal oils may be further treated and part of the hydrocarbons converted into 1 phenolic bodies by any of the well known meth- 1 ads, such as fusion of the sulfonateswith causo tic potash or by the diazo reaction, and the resulting phenolic compounds may be isolated in a partially purified form and mixed with a residual highly cracked hydrogenated or unhydrogenated -cyclestocktbgiveamixturethatclcselyresembles coal tar creosote. Petroleum products or other products of a pitchy nature ormerely of a high boiling range may also be added to the mixture in order to obtain a resultant mixture which is efiective over a longer period of time, and which, for example, may contain a residue above 671 F. which varies between 5 and 50% of the resultant V mixture.

These herbicidal oils maybe further treated to increase their efliciency, i. e. by the addition of small amounts of phenols, cresols, etc. or the following substances which are principally compounds of arsenic, copper or mercury: Copper naphthenate; copper sulfonatei diphenylamine chlorarsine; phenyl arsinous oxide; mercuric oxide; mercuric chloride; mercuric arsenate; cuprous cyanide; cupric orthonitrobenzoate; mercuric anilenate; crystal violet; methylene blue. Alternately small amounts of substances such as alpha or betanaphthol increase the toxic efliciency of the higher boiling fractions which are preferably used.

- These herbicidal oils are sprayed over the weeds and at least 3 to 4 ounces are used for every 100 square feet of surface. Usually two or three applications are sufficient to kill all the weeds. After the weeds are once all killed oil about three or four applications a year are sumcient to keep the surface free of weeds. These herbicidal oils are also toxic to insects and larvae. They readily spread when applied to the surface of water and owing to their high boiling points are eifective over a long period of time. When sprayed over the ground in preparation for construction they can be used to kill off they vegetation together with the termites, etc. as the herbicidal oils are of low viscosity and will readily soak into the ground. When used on insects other insecticidal ingredients may be added, for example pyrethrum and derris extracts.

These herbicidal oils are especially useful in controlling marine growth when used alone on fish nets, ropes, etc. or incorporated in marine paints. The herbicidal oils when used in marine paints are preferably used together with some of the above compounds of arsenic, copper and/0r mercury. Nets and ship bottoms when treated with these herbicidal oils are kept free of marine vegetation and also other undesirable growths such as barnacles, etc. The herbicidal oils used in paints, etc. can be first resinifled for example, by'condensation'with ethylene dichloride in the presence 'of aluminum chloride. A partial resinification of these hydrogenated and highly cracked fractions results in a product containing sufilcient polymerized and condensed molecules to ensure a tough film, but also containing enough of the lower boiling substances to impart considerable toxicity.

The foregoing description is merely illustrative and various changes and alternative arrangements may be made within the scope of the appended claims in which it is our intention to claim all inherent novelty in the invention as broadly as the prior art permits.

We claim:

1. A herbicidal hydroformed petroleum oil of an aniline point of about 20 to -80 F. and a gravity of about 8 to 20 A. P. I.

2. A herbicidal oil comprising a hydroformed petroleum oil composed substantially of aromatic, naphthenic, and unsaturated hydrocarbons and having an aniline point of about 20 to --80 F. and a gravity of about 8 to 20 A. P. I. 8. A herbicidal 011 comprising a petroleum oil fraction obtained by the use of a selective solvent and composed substantially of aromatic, naphthenic and unsaturated hydrocarbons having an aniline point of about 20 to 80 F. and agravity of about 8 to 20 A. P. I.

.4. A herbicidal oil comprising a liquid product rated hydrocarbons having an aniline point of about 20 to 80 F. and a gravity of about 8 to 20 A. P. I. and obtained by hydrogenating a composed substantially of aromatic and unsatu- 

